CZ296227B6 - Synergistic herbicidal composition comprising mesotrione and method for controlling undesirable vegetation using such a composition - Google Patents

Abstract

In the present invention, there is disclosed a synergistic herbicidal composition comprising; (A) mesotrione, and: (B) a second herbicide being selected from the group consisting of amicarbazone, triazinones, imidazolinones, dicamba, flumetsulam, trifloxysulfuron, tritosulfuron, triasulfuron, pyriftalid, prosulfocarb, cinosulfuron, or their herbicidally active salts wherein the weight ratio of component (A) to component (B) is between about 32: 1 and about 1: 20. Disclosed is also a method of controlling the growth of undesirable vegetation, particularly in crops, using the above-described synergistic composition.

Description

Technical field

The present invention relates to a herbicidal composition comprising (A) mesotrione and (B) a second herbicidal compound. The invention also relates to a method for controlling the growth of undesirable vegetation, in particular in crop plants, by means of this composition.

BACKGROUND OF THE INVENTION

Protecting crops from weeds and other vegetation that hampers growth is an ever-recurring problem in agriculture. To help combat this problem, researchers in the field of synthetic chemistry have produced a wide range of chemicals and chemical preparations effective to control such unwanted growth. Chemical herbicides of many types have been described in the literature and many of them are commercially used.

In some cases, herbicidally active substances have been shown to be more effective in combination than when applied individually, and this is referred to as "synergism". As defined in the Herbicide Handbook of the Weed Science Society of America, Seventh Edition, 1994, p. 318, '' synergism 'is such an interaction of two or more factors that the effect, when combined, is greater than the effect predicted by responses to each of the factors applied separately ”. The present invention is based on the discovery that mesotrione and certain other herbicides exhibit a synergistic effect when applied in combination.

The herbicidal compounds forming the synergistic compositions of the present invention are independently known in the art for their effects on plant growth. All are described in The Pesticides Manual, Twelfth Edition, 2000, published by The British Crop Protection Council. They are also commercially available.

SUMMARY OF THE INVENTION

The present invention relates to a synergistic herbicidal composition comprising (A) mesotrione, and (B) a second herbicide selected from the group consisting of:

(B2) amicarbazone;

(B3) a triazinone of the formula:

O

In which

Y represents an alkyl group having 1 to 8 carbon atoms, preferably an alkyl group having 2 to 6 carbon atoms, or a cycloalkyl group having 5 to 7 carbon atoms, preferably a cyclohexyl group, or an aryl group, for example a phenyl group;

Z represents an alkyl group having 1 to 6 carbon atoms, preferably a methyl group, or an alkoxy group having 1 to 6 carbon atoms, or an alkyl mercapto group having 1 to 6 carbon atoms, preferably a methylmercapto group;

(B4) an imidazolinone of the formula:

in which

Z is CH or N;

B represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 1 to 6 carbon atoms in the alkyl moiety and 1 to 6 carbon atoms in the alkoxy moiety;

A represents a hydrogen atom, or

A and B together form an aromatic ring;

(B5) dicamba;

(B6) flumetsulam;

(B7) trifloxysulfuron;

(B8) tritosulfuron;

(B9) triasulfuron (BIO) pyriftalid;

(B11) prosulfocarb;

(B13) cinosulfuron;

or a herbicidally active salt thereof, wherein the weight ratio of component (A) to component (B) is between about 32: 1 and 1:20.

-2GB 296227 B6

The synergistic compositions of the present invention can provide one or more of many advantages over the use of the individual components (A) and (B). Application rates of the individual components can be significantly reduced while maintaining a high level of herbicidal activity. The composition may have a significantly broader spectrum of weeds against which it is effective than each of the components alone. The Kom5 position shows the potential to control weed species at a low rate of application at which the individual compounds were themselves ineffective. The compositions may exhibit a rate of action that is higher than the rate that would be predicted from the rate of the individual components.

The composition comprises a herbicidally effective amount of a combination of component (A) and component (B). The term "herbicide" as used herein means a compound that regulates or modifies plant growth.

The term "herbicidally effective amount" means an amount of such a compound or combination of such compounds that is capable of producing a regulating or modifying effect on plant growth.

Regulatory or modifying effects include all deviations from natural development, eg15 fallow: killing, retardation, leaf burning, albinism, stunting, etc. The term "plants" refers to all physical parts of a plant, including seeds, seedlings, trees, roots, tubers, stems, stems , foliage and fruits.

Mesotrione may be used in the form of a metal salt or chelate such as copper chelate. Most preferably, the me20 sotrione is in the form of a copper chelate. Mesotrione metal chelates and their preparation are known and described in US 5,912,207.

Examples of triazinones are metamitron and metribuzin.

In the general formula

Z preferably represents a nitrogen atom. B preferably represents a methyl group, an ethyl group or a methoxyethyl group, or A and B represent an unsubstituted aromatic ring. Examples of imidazolinones are imazapic, imazapyr, imazamethabenzmethyl, imaza30 quin, imazamox and imazethapyr.

Dicamba may be in the form of a salt, such as a sodium, potassium or ammonium salt.

Trifloxysulfuron may be in the form of a salt, such as a sodium salt.

Component (B) is preferably dicamba, flumetsulam, imazamox, imazapyr, imazethapyr, metribuzin, trifloxysulfuron or pyriftalid. Other herbicides may also be added to the compositions. For example, sulfonylureas such as nicosulfuron, prosulfuron, bensulfuron may be added to the mixture of mesotrione and pyriftalide for use in rice.

The present invention also relates to a method for controlling the growth of undesirable vegetation, particularly in crop plants, and to the use of this synergistic composition.

The species spectra of compounds (A) and (B), ie the weed species that regulate the compounds, are broad and highly complementary. Mesotrione controls most broadleaf weeds and low grass weeds, and compounds (B) control most broadleaf weeds and few or some broadleaf weeds. The second spectrum of the individual compounds within the scope of the present invention varies to some extent. However, it has surprisingly been found that the combination of compounds (A) and (B) has a synergistic effect in controlling many common weeds.

The weight ratio of component (A) to component (B) in the compositions of the present invention is preferably between about 8: 1 to 1:15, with a weight ratio between about 4: 1 and about 1:10 being particularly preferred.

DETAILED DESCRIPTION OF THE INVENTION

The extent to which the synergistic composition of the invention is applied depends on the particular type of controlled weed, the degree of control and timing desired and the method of application. In general, the compositions of the invention may be applied at an application rate of between about 0.005 kg / ha (kg / ha) and about 5.0 kg / ha based on the total weight of the active ingredient (component (A) + component (B)) in the composition . A preferred rate of application is between about 0.5 kg / ha and 3.0 kg / ha. In a particularly preferred embodiment of the present invention, the composition comprises components (A) and (B) in relative amounts sufficient to provide a rate of application of at least 1.0 kg / ha, of which component (A) provides at least 0.02 kg / ha.

The compositions of the present invention are useful as herbicides having synergistic effects in the control of undesirable vegetation. The compositions may be formulated in the same manner as herbicides are generally formulated. The compounds may be applied either alone or combined as part of a two-part herbicidal system.

The purpose of the formulation is to apply the composition in an appropriate manner to a site where regulation is desired. The term 'site' is intended to include soil, seeds and seedlings as well as established vegetation.

The composition can be applied to a wide variety of cropland such as corn, wheat, rice, tomato or sugar cane. Suitable stands include stands that are tolerant to one or more of (A) or (B), or any other herbicide such as glyphosate, which may be further included in the composition. Tolerance can be natural tolerance created by selective breeding or can be achieved artificially by genetic modification of the stand. Tolerance means reduced susceptibility to damage caused by a particular herbicide compared to conventional plant species. The stands can be modified or bred to be tolerant to, for example, HPPD inhibitors such as mesotrione or EPSPS inhibitors such as glyphosate. Corn is inherently tolerant to mesotrione.

The compositions used within the scope of the present invention can be applied in various concentrations known to those skilled in the art. The composition can be used to control the growth of unwanted vegetation using pre-emergence or post-emergence application to a site where control is desired. The compositions of the present invention are particularly effective when applied preemergently.

The synergistic herbicidal compositions of the present invention preferably also comprise an agriculturally acceptable carrier. In practice, the composition is applied as a preparation containing various excipients and carriers known or used in the industry to facilitate dispersion. The choice of formulation and route of administration for any given compound can affect its activity, and the choice is made accordingly. Thus, the composition of the invention may be formulated as granules, as wettable powders, as emulsifiable concentrates, as powders or dusts, as liquid preparations, as solutions, as suspensions or emulsions, or as controlled release forms such as microcapsules. These preparations may contain as little as about 0.5% to as much as about 95% by weight. or more active ingredient. The optimum amount for any given compound will depend upon the formulation, application equipment, and nature of the controlled plants.

-4GB 296227 B6

Wettable powders are in the form of finely divided particles that readily disperse in water or other liquid carriers. The particles contain the active substance stored in a solid matrix. Typical solid matrices include fuller clay, kaolin clays, silicas and other easily wettable organic or inorganic solids. Wettable powders normally contain from about 5% to about 95% of the active ingredient plus a small amount of wetting, dispersing or emulsifying agent.

Emulsifiable concentrates are homogeneous liquid compositions dispersible in water or other liquid, and may consist solely of the active compound with a liquid or solid emulsifier or may also contain a liquid carrier such as xylenes, heavy aromatic petroleum fractions, isaphorone and other non-volatile organic solvents. In use, these concentrates disperse in water or other liquid and are normally applied as a spray to the area to be treated. The amount of active ingredient may range from about 0.5% to about 95% of the concentrate.

Granular formulations include both extrudates and relatively coarse particles, and are usually applied without dilution to the area where vegetation control is desired. Typical carriers for granular formulations include sand, fuller's clay, attapulgite clay, bentonite clays, montmorillonite clay, vermiculite, perlite and other organic or inorganic materials that absorb the active compound or which may be coated with the active compound. Granular formulations normally contain from about 5% to about 25% of the active ingredients, which may include surfactants such as heavy aromatic petroleum fractions, carosene and other petroleum fractions, or vegetable oils; and / or binders (adhesives) such as dextrins, glues or synthetic resins.

Dusts are free-flowing mixtures of the active ingredient with finely divided solids such as talc, clays, flours and other organic and inorganic solids which act as dispersants and carriers.

Microcapsules are typically drops or granules of the active ingredient enclosed in an inert porous sheath that allows the enclosed material to escape into the environment at controlled rates. The encapsulated drops typically have a diameter of about 1 to 50 µm. The sealed liquid typically constitutes about 50 to 95% by weight of the capsule and may include a solvent in addition to the active agent. Encapsulated granules are generally porous granules with porous membranes closing the pore openings of the granules, keeping the active substances in liquid form within the granule pores. The diameter of the granules is typically from 1 millimeter to 1 centimeter, preferably from 1 to 2 millimeters. Granules are formed by extrusion, agglomeration or solidification, or occur naturally. Examples of such materials are vermiculite, sintered clay, kaolin, attapulgite clay, sawdust and granular carbon. Housing or membrane materials include natural and synthetic gums, cellulosic materials, styrene-butadiene copolymers, polyacrylonitriles, polyacrylates, polyesters, polyamides, polyureas, polyurethanes and starch xanthates.

Other useful herbicide formulations include simple solutions of the active ingredient in a solvent in which it is completely soluble at the desired concentration, such as acetone, alkylated naphthalenes, xylene, and other organic solvents. Pressure nebulizers can also be used where the active ingredient is dispersed in finely divided form as a result of evaporation of the low boiling dispersing solvent carrier.

Many of these formulations contain wetting, dispersing, or emulsifying agents. Examples are alkyl and alkylaryl sulfonates and sulfates and salts thereof; polyhydric alcohols; polyethoxylated alcohols; esters and fatty amines. These agents, when used, normally comprise from 0.1% to 15% by weight. preparation.

Each of the above formulations can be prepared as a package containing the herbicide together with other formulation ingredients (diluents, emulsifiers, surfactants, etc.). Preparations can also be prepared using a tank blending method in which the substances are obtained individually and mixed at the place of cultivation.

-5GB 296227 B6

These compositions can be applied to the areas where control is required by conventional methods. Dusts and liquid compositions can be applied, for example, using mechanical dusters, spreading and hand sprays, and spray dusters. The formulations can also be applied from aircraft in the form of a powder or spray application or a rope wick application. To modify or control the growth of germinating seeds or emerging seedlings, the dusting or liquid formulations can be spread in the soil to a depth of at least half an inch below the ground surface or applied only to the soil surface by spraying or sprinkling. The formulations can also be applied by adding to the irrigation water. This allows the preparations to enter the soil together with the irrigation water. Dust compositions, granular compositions or liquid formulations applied to the soil surface can be expanded 10 below the soil surface by conventional methods such as plate, gate or mixing operations.

If necessary or desired for a particular application or crop, the composition of the present invention may contain an antidotally effective amount of an antidote of component (A) and component (B). Suitable antidotes are well known to those skilled in the art. Examples of suitable antidotes are benoxa15 cor and cloquintocet-mexyl.

Further, other biocidal active ingredients or compositions may be combined with the synergistic herbicidal composition of the present invention. The compositions may contain, for example, insecticides, fungicides, bactericides, acaracides or 20 nematicides, in addition to components (A) and (B), in order to extend the spectrum of action.

As one skilled in the art, when testing herbicides, is aware of a significant number of factors that are not readily controllable, it can affect the results of individual tests and render them non-reproducible. For example, the results may vary depending on environmental factors such as 25 on, among other factors, the amount of sunlight and water, soil type, soil pH, temperature and humidity. The test results can also be influenced by the planting depth, the rate of application of single and combined herbicides, the rate of application of any antidote and the ratio of the individual herbicides and / or antidotes, as well as the nature of the stands or weeds tested. Results may vary from crop to crop, within crop varieties, may vary.

Although the invention has been described with reference to preferred embodiments and examples thereof, the scope of the present invention is not limited to the described embodiments. As will be apparent to one skilled in the art, modifications and adaptations of the above-described invention may be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (8)

PATENT CLAIMS 1. A synergistic herbicidal composition comprising: (A) mesotrione, and (B) a second herbicide selected from the group consisting of: (B2) amicarbazone; (B3) a triazinone of the formula: in which Y represents an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 5 to 7 carbon atoms or an aryl group; Z represents an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms or an alkylmercapto group having 1 to 6 carbon atoms; (B4) an imidazolinone of the formula: in which Z is CH or N; B represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 1 to 6 carbon atoms in the alkyl moiety and 1 to 6 carbon atoms in the alkoxy moiety; A represents a hydrogen atom, or A and B together form an aromatic ring; (B5) dicamba; (B6) flumetsulam; (B7) trifloxysulfuron; (B8) tritosulfuron; (B9) triasulfuron (BIO) pyriftalid; (B11) prosulfocarb; (B13) cinosulfuron; or a herbicidally active salt thereof, wherein the weight ratio of component (A) to component (B) is between about 32: 1 and 1:20. The herbicidal composition according to claim 1, wherein component (B) is dicamba, flumetsulam, imazamox, imazapyr, imazethapyr, metribuzin, trifloxysulfuron or pyriftalid. The herbicidal composition according to claim 1 or 2, characterized in that the weight ratio of component (A) to component (B) is between 8: 1 and 1:15. The herbicidal composition of claim 3, wherein the weight ratio of component (A) to component (B) is between 4: 1 and 1:10. 5. A method of controlling undesirable vegetation, comprising applying to the site of such vegetation a herbicidally effective amount of the composition of claim 1. 6. The method according to claim 5, wherein the combined amount of components (A) and (B) applied to the site of undesirable vegetation is between 0.005 kg / ha and 5.0 kg / ha. Method according to claim 6, characterized in that the combined amount of components (A) and (B) applied to the site of undesirable vegetation is between 0.5 kg / ha and 3.0 kg / ha. Method according to claim 7, characterized in that the combined amount of components (A) and (B) applied to the site of undesirable vegetation is at least 1.0 kg / ha, wherein at least 0.02 kg / ha is applied to the site of undesirable vegetation of component (A).